rgslccorr is the task that allows the user to create RGS lightcurves. The task corrects the lightcurve from:
This task needs as mandatory input parameters a RGS event list, the corresponding RGS source list and a timebinsize. It is also possible to create a lightcurve of the two intruments(RGS1+RGS2), if the two events list belong to the same observation and the two instrument exposure were taken simultaneously.